A teacher wants to know if burning a scented candle affects students’ performance on pop quizzes. In the experiment, there will be a treatment group and a control group each taking their quizzes in a room that either does or does not have a scented candle burning. Why is randomization important when setting up an experiment to answer this research question?

to ensure that both groups have a nice mix of students

to ensure that the two groups have the same number of students

to ensure that both groups are roughly equivalent regarding students’ preparedness, anxiety levels, and study skills

to ensure that the rooms for both groups are approximately the same regarding time of day, temperature, sound control, and lighting

A researcher wants to know if eating a mint affects whether people can distinguish between two popular orange juice brands. To conduct an experiment, the researcher places participants in two groups. The treatment group w